Play Tweakers

My (23f) roommate(20f) lives with me in a 3 bedroom condo. It's divided with a room for each of us and then an office for my schoolwork and for her to do hair. My roommate entered the contract with 1 cat, uno. Then came dos, a severely malnourished kitten who we found on the side of the road. Dos has gotten healthier over the months, or so we thought. Nope, the cat was fucking pregnant and gave birth on a random Tuesday. My roommate won't vaccinate the mom or child or nuter the cats because she can't afford it yet(dos needs her tail amputated from it breaking wrong before we got her but that hasnt happened either). My roommate promised to give away the baby but now she's refusing to, saying that she wants to keep him. Three things wrong with that:

1. I have a massive dog that the cats HATE, so the cats are all kept in her small room all day. That feels very unfair to them.
2. I gave my roommate a years notice about adopting a dog, and gave her multiple updates, letting her know I would drop it if she asked bc it's her house too. I get no notice, no asking if I'm ok with it, nothing.
3. she can't afford the cats she already has. Dos bit her and she had to go to urgent care bc the cat. isn't. VACCINATED.
4. Am I the A-hole?

Edit:
The rule about the cats staying in her room was made by her at the start of th lease because Uno likes to get stuck in weird places and try to escape out the front door. We also have 3 flights of stairs inside our condo.
I will not be moving as I lived here first and I just moved last year. She moved in a couple months after me.